i need to know the keycode for 5000 rds e.o.n?

I have tried to enter the keycode i have for my 5000 rds 7 times and i think it must be wrong could you confirm this my code is 1456. Serial No. M311939
Part No. 98ap-18k876-ba. if the keycode is right could you give me instructions on how to enter this as this could be what i'm doing wrong. I have no book as it is a second hand car. Thanks. THERESA SMITH